It's a guitar strap button locker pin and also can be used as a keychain. based on my son's request to made him a locker pin for his loose guitar strap that sometimes suddenly detached from the button while it's used, but I'm adding more function as a keychain with the cute ghost that hugging pumpkin part. This design has been tested on my son's music performance before, and successfully help him with no more detached guitar strap accident.

I didn't measure other guitar strap button size, but I guess there's not much differences between them as long as the button models are similar, this problem can be solved by scaling the models before printing.

Print Setting :

Default 0.2 layer height 0.4 wall line width no support test print using easy ABS on Bambulab A1 mini